Conventionally, there has been proposed a connector device that comprises a hollow cylindrical connector socket and a hollow cylindrical connector plug which is inserted into the connector socket (see Japanese Laid-Open Patent Publication (Kokai) No. 2000-228250).
The connector socket has two rectangle holes formed therein. The two rectangle holes are opposed to each other in the radial direction of the connector socket.
The connector plug includes two spring pieces extending along a direction of the central axis thereof, which are positioned symmetrically with respect to the central axis of the connector plug. A free end of each spring piece is formed with a locking lug which can be engaged in an associated one of the rectangle holes of the connector socket. The locking lug is formed with an inclined surface for disengaging between the locking lug and the associated rectangle hole.
When the connector plug is inserted (fitted) into the connector socket and the connector plug is rotated in a predetermined direction, the locking lugs of the spring pieces of the connector plug are engaged in the respective rectangle holes of the connector socket, whereby the connector plug is locked to the connector socket, which maintains a state of the two connectors fitted to each other. On the other hand, when the connector plug is rotated in an opposite direction from the predetermined direction from a state in which the connector plug is locked to the connector socket, the engagement between the locking lugs of the spring pieces of the connector plug and the rectangle holes of the connector socket is released, whereby the connector socket and the connector plug are released from the state locked to each other.
As another conventional technique for this connector device, there has been proposed a connector device in which even if a plug connector is rotated in any direction from the state in which the plug connector is locked to a receptacle connector, the engagement between locking lugs of spring pieces of the plug connector and respective rectangle holes of the receptacle connector is prevented from being released. In this connector device, the plug connector can be removed from the receptacle connector by simultaneously putting ends of two screwdrivers into the respective rectangle holes of the receptacle connector to thereby release the engagement between the locking lugs of the spring pieces and the rectangle holes, and pulling the plug connector in this state.